Cermetek Microelectronics, Inc.
CH1788 Surface Mount PLCC 2400bps Modem
2006 Cermetek Microelectronics, Inc.
Page 11
Document No. 607-0018 Revision A6 (01/06)
IMPORTANT NOTE
The tables included in this data sheet are a
summary of the AT commands and S-Registers. A
detailed description of all commands and registers is
available from Cermetek Microelectronics, Inc., and
should be consulted prior to design. Refer to
Cermetek publication CH1788 AT Commands and
S-Registers Reference Guide or access our website
at
http://www.cermetek.com
.
Table 5. CH1788 AT Command Set Summary.
Basic
Commands
Function
AT Attention
Code
A Answer
command
A/
Repeat last Command
C
Carrier Detect DCD Signal Monitor
D Dial
Command
E
Off-Line Character Echo Option
F
Load Factory Default
H
Switch Hook Control Option
I Identification
Option
K
DCE-DTE Flow Control
L
Fast Connect Option
N
Data Set Ready DSR Signal
Monitor
O On-Line
Command
P Pulse
Dial
Q
Result Code Display Option
R
Data Terminal Ready DTR Monitor
S
S Register Monitor
T Tone
Dialing
V
Verbose / Numeric Result Codes
W
Extended Result Codes
X
Result Code Set/Call Progress
Y
Async. Speed Buffered Option.
Z Reset
@T Test
Modes
@Z Power
Down
+++ Escape
Sequence
PSTN LINE CONNECTION GUIDELINES
1. The CH1788 must be mounted in the final
assembly such that it is isolated from exposure to
any hazardous voltages within the assembly.
Adequate separation and restraint of cables and
cords must be provided.
2. The circuitry from the CH1788 to the telephone
line interface must be provided in wiring that
carries no other circuitry other than that
specifically allowed in the FCC rules.
3. Connection to phone line should be made
through an approved RJ-11C jack.
4. PCB traces from the modem’s RING and TIP pins
to the RJ-11C jack must be 0.1 inch spacing or
greater to one another and 0.2 inch spacing or
greater to all other traces. The traces should
have a nominal width of 0.020 inches or greater.
5. The RING and TIP PCB traces should be as
short as possible and oriented to prevent
coupling other high speed or high frequency
signals present on the host circuit PCB.
6. No additional circuitry other than that shown may
be connected between the modem module and
the RJ-11C jack. Doing so will invalidate the
FCC approval.
7. The CH1788 requires external surge protection.
This is mandatory to maintain FCC Part 68
conveyed approval. Please use only
recommended components and values. Do not
use an MOV or a Transorb.
8. The CH1788, the RJ-11C jack, the protection
circuitry and all PCB traces in between, must be
contained on a PCB with a 94 V-0 flammability
rating.
9. The supplied FCC registration label must be
applied visibly on the outside of the product.
10. The product’s User Manual must provide the user
with instructions for connection and use as
recommended in the FCC Registration Section
below.
CH1788 HANDLING AND ASSEMBLY
RECOMMENDATIONS
The CH1788 contains static-sensitive components
and should only be handled by personnel and in
areas that are properly protected against static
discharge.
Direct Soldering.
The CH1788 requires hand
soldered. All CH1788 products are moisture resistant
and will not be harmed by industry standard aqueous
cleaning processes. Cermetek does NOT
recommend SMD or wave soldering. Cermetek
recommends against socketing the modem for
production products. However, for development
purposes, a 68 pin PLCC socket may be used.
FCC REGISTRATION
The CH1788 is registered with the FCC (Federal
Communications Commission) under Part 68. To
maintain the validity of the registration, the end
product supplier must notify to the end user of the
product of several restrictions the FCC places on the
CH1788 and its use.
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